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Appositional angle closure and conversion of primary angle closure into glaucoma after laser peripheral iridotomy
Li Qiu1,2, Yujie Yan1,3, Lingling Wu4
1Department of Ophthalmology, Peking University Third Hospital, Beijing, China.
The British Journal of Ophthalmology
|June 5, 2019
Summary
Appositional angle closure (AppAC) greater than two quadrants significantly increases the risk of primary angle closure (PAC) converting to primary angle closure glaucoma (PACG) post-laser peripheral iridotomy (LPI). Older age and higher vertical cup-to-disc ratio (VCDR) also predict conversion.
Area of Science:
- Ophthalmology
- Glaucoma Research
- Anatomic Studies
Background:
- Primary angle closure (PAC) is a leading cause of irreversible blindness globally.
- Laser peripheral iridotomy (LPI) is a common treatment for PAC, aiming to prevent progression to primary angle closure glaucoma (PACG).
- The role of appositional angle closure (AppAC) in PAC progression post-LPI requires further elucidation.
Purpose of the Study:
- To investigate the association between baseline appositional angle closure (AppAC) and the conversion of PAC to PACG after LPI.
- To identify other risk factors contributing to PAC conversion post-LPI.
Main Methods:
- Prospective cohort study analyzing 80 eyes from 58 PAC patients who underwent LPI.
- Baseline AppAC assessed via ultrasound biomicroscopy; PAC conversion defined by glaucomatous optic neuropathy and visual field defects.
- Follow-up for at least 5 years with a minimum of 5 visual field tests; logistic regression used for risk factor analysis.
Main Results:
- 25% of PAC eyes converted to PACG over a mean follow-up of 6.67 years.
- Eyes with AppAC > 2 quadrants at baseline showed a significantly higher conversion rate (58.3%) compared to those with AppAC ≤ 2 quadrants (19.1%).
- Older age and higher baseline vertical cup-to-disc ratio (VCDR) were significantly associated with PAC conversion.
Conclusions:
- AppAC > 2 quadrants is a significant predictor of PAC to PACG conversion after LPI.
- Older age and higher VCDR are also risk factors for conversion in PAC patients treated with LPI.
- These findings highlight the importance of baseline AppAC assessment for risk stratification and management in PAC.
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